So-called chuunibyou means "having a rich inner life: imagining stories with yourself as the protagonist, embellishing your experiences, and picturing yourself doing amazing things." Yu Meng thinks that apart from having a rich inner life and a wild imagination, she doesn't really fit the description. Unfortunately...
"Stop making excuses. You're just chuunibyou!"
Yu Meng was left speechless. Fine, chuunibyou it is.
"But seriously, the thousand-year Holy War of the vampires really is about to begin, and it seems to overlap with the Holy War between Heaven and Hell. That's true."
Everyone: Heh.
Yu Meng: Believe me! Believe me! What I'm saying is absolutely true!
Everyone: Heh.
The real former saint, former third-generation vampire, now human Yu Meng: So the world's destruction is definitely not my fault!
[Revising the story. I recommend rereading it (covers face).]